The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

Coroner's ruling on 1970s nurses case soon

A coroner will soon hand down his findings into the brutal deaths of two nurses in the 1970s, potentially ending one of Australia's most prolific crime mysteries.

Wendy Evans and Lorraine Wilson went missing while hitchhiking in Queensland in 1972 and their bodies were found in bushland two years later.

Their killers have never been identified and their deaths have been the subject of a recent inquest in the hope of shedding light on their fate.

State Coroner Michael Barnes will hand down his findings in Brisbane Magistrates Court on Friday.

But determining who was responsible for the nurses' death could prove difficult.

The inquest has heard the only suspect against whom there is enough evidence to stand trial, Wayne "Boogie" Hilton, has since died.

Counsel assisting the coroner Craig Chowdhury earlier told the inquest Mr Hilton had tearfully confessed to their deaths, had been seen pulling stained carpet from his car in the middle of the night, and had often boasted about violently raping women in the bush.